N.Y.C. Admin. Code § PC 1303: Section PC 1303: Nonpotable Rainwater Collection and Conveyance Systems

1303.1 General.

The provisions of Section

1303

shall govern the construction, installation, alteration and repair of rainwater collection and conveyance systems for the collection, storage, treatment and conveyance of rainwater for nonpotable applications, as permitted by the

New York City Construction Codes

, and all applicable laws, and rules, including but not limited to those of the Department of Environmental Protection and the Department of Health and Mental Hygiene.

1303.2 Collection surface.

Rainwater shall be collected only from above-ground impervious roofing surfaces constructed from approved materials. Collection of water from vehicular parking or pedestrian surfaces shall be prohibited except where the water is used exclusively for landscape irrigation.

1303.2.1 Prohibited sources.

Roof mounted appliances and equipment including but not limited to evaporative coolers, cooling towers, water heaters, and solar water heaters shall not discharge onto rainwater collection surfaces.

1303.3 Debris excluders.

Downspouts and leaders shall be connected to a roof washer and shall be equipped with a debris excluder or equivalent device to prevent the contamination of collected rainwater with leaves, sticks, pine needles and similar material. Debris excluders and equivalent devices shall be self-cleaning.

1303.4 Roof washer.

A sufficient amount of rainwater shall be diverted at the beginning of each rain event, and not allowed to enter the storage tank, to wash accumulated debris from the collection surface. The amount of rainfall to be diverted shall be field adjustable as necessary to minimize storage tank water contamination. The roof washer shall not rely on manually operated valves or devices, and shall operate automatically. Diverted rainwater shall not be drained to the roof surface, and shall be discharged in a manner consistent with the storm water runoff requirements of the Department of Environmental Protection and this code. Roof washers shall be accessible for maintenance and service.

1303.5 Roof gutters and downspouts.

Gutters and downspouts shall be constructed of materials that are compatible with the collection surface and the rainwater quality for the desired end use. Joints shall be water tight.

1303.5.1 Slope.

Roof gutters, leaders and rainwater collection piping shall slope continuously toward collection inlets. Gutters and downspouts shall have a slope of not less than 1/8 inch per foot (10.4 mm/m) along their entire length, and shall not permit the collection or pooling of water at any point.

Exception:

Siphonic drainage systems installed in accordance with the manufacturer's instructions shall not be required to have a slope.

1303.5.2 Size.

Gutters and downspouts shall be installed and sized in accordance with Section

1106

.

1303.5.3 Cleanouts.

Cleanouts shall be provided in accordance with

Chapter 11

of this code in the water conveyance system and to allow access

to all filters, flushes, pipes and downspouts.

1303.6 Drainage.

Water drained from the roof washer or debris excluder shall not be drained to the sanitary sewer. Such water shall be diverted from the storage tank and discharge in a location that will not cause erosion or damage to property in accordance with the

New York City Building Code

. Roof washers and debris excluders shall be provided with an automatic means of self-draining between rain events, and shall not drain onto roof surfaces.

1303.7 Collection pipe.

Rainwater collection and conveyance systems shall utilize drainage piping approved

for use within plumbing drainage systems to collect and convey captured rainwater. Vent piping approved

for use within plumbing venting systems shall be utilized for vents within the rainwater system. Collection and vent piping materials shall comply with Section

1102

.

1303.7.1 Installation.

Collection piping conveying captured rainwater shall be installed in accordance with

Chapter 11

.

1303.7.2 Joints.

Collection piping conveying captured rainwater shall utilize joints approved

for use with the piping and appropriate for the intended applications as specified in

Chapter 11

.

1303.7.3 Size.

Collection piping conveying captured rainwater shall be sized in accordance with drainage sizing requirements specified in Section

1106

.

1303.7.4 Labeling and marking.

Additional marking of collection piping containing captured rainwater for reuse shall be identified in accordance with Section 704.7.

1303.8 Filtration.

Untreated rainwater collected for reuse shall be filtered as required for the intended nonpotable end use as established by the Department of Health and Mental Hygiene. Filters shall be accessible for inspection and maintenance. Filters shall utilize a pressure gauge or other approved

method to provide indication when a filter requires servicing or replacement. Filters shall be installed with shutoff valves installed immediately upstream and downstream to allow for isolation during maintenance.

1303.8.1 Filtration required.

Nonpotable water utilized for water closet and urinal flushing applications shall be filtered by a 100-micron or finer filter.

1303.9 Disinfection.

Untreated rainwater collected for reuse shall be disinfected and treated as required for the intended nonpotable end use as established by the Department of Health and Mental Hygiene.

1303.10 Storage tanks.

Storage tanks utilized in nonpotable rainwater collection and conveyance systems shall comply with Sections 1301.9 and 1303.10.1 through 1303.10.4.

1303.10.1 Location.

Storage tanks shall be located with a minimum horizontal distance between various elements as indicated in

Table 1303.10.1

.

Table 1303.10.1 Location of Rainwater Storage Tanks

Element

Minimum Horizontal Distance from Storage Tank (feet)

Critical root zone (CRZ) of protected trees

2

Lot line adjoining private lots

5

Seepage pits

5

Septic tanks

5

For SI: 1 foot = 304.8 mm.

1303.10.2. Design and construction.

Storage tanks shall be designed and constructed in accordance with

Chapters 16

through

22

of the

New York City Building Code

and in accordance with the following standards, as appropriate for the material of the storage tank: AWWA D100, AWWA D115, AWWA D120, UL 58, UL 1746, UL 1316, UL 142, API 12F or API 12D.

1303.10.3 Inlets.

Storage tank inlets shall be designed to introduce collected rainwater into the tank with minimum turbulence, and shall be located and designed to avoid agitating the contents of the storage tank.

1303.10.4 Outlets.

Outlets shall be located at least 4 inches (102 mm) above the bottom of the storage tank and shall not skim water from the surface.

1303.11 Valves.

Valves shall be provided in accordance with Sections 1303.11.1 through 1303.11.3.

1303.11.1 Collection piping bypass valve.

One full-size three-way diverter valve shall be installed on collection piping upstream of each storage tank, or drainfield, as applicable, to divert untreated rainwater to the storm or combined sewer

to allow servicing and inspection of the system. Bypass valves shall be marked to indicate the direction of flow, connection and storage tank or drainfield connection. Bypass valves shall be installed in accessible locations. Two shutoff valves shall not be installed to serve as a bypass valve.

1303.11.2 Backwater valve.

One or more backwater valves shall be installed on each overflow and tank drain pipe. Backwater valves shall be in accordance with Section

1101

.

1303.11.3 Conveyance piping bypass valve.

One full-size three-way diverter valve shall be installed on the conveyance piping system upstream and downstream of all treated storage tanks, as applicable, to divert treated on-site nonpotable reuse water to the sanitary sewer to allow system testing, commissioning and bypass conditions.

1303.12 Pumping and control system.

Mechanical equipment including pumps, valves and filters shall be easily accessible and removable in order to perform repair, maintenance and cleaning. The minimum flow rate and flow pressure delivered by the pumping system shall be appropriate for the application and in accordance with Section

604

.

1303.13 Water pressure-reducing valve or regulator.

Where the water pressure supplied by the pumping system exceeds 85 psi (587 kPa) static, a pressure-reducing valve shall be installed to reduce the pressure in the rainwater conveyance system piping to 85 psi (587 kPa) static or less. Pressure- reducing valves shall be specified and installed in accordance with Section 604.8.

1303.14 Conveyance pipe.

Conveyance piping utilized in rainwater collection and conveyance systems shall comply with Sections 1303.14.1 through 1303.14.3.

Exception:

Irrigation piping located outside of the building and downstream of a backflow preventer.

1303.14.1 Materials, joints and connections.

Conveyance piping shall conform to the standards and requirements specified in Section 1301.6.

1303.14.2 Design.

Rainwater reuse conveyance piping systems shall be designed and sized in accordance with Section

604

for the intended application.

1303.14.3 Marking.

Nonpotable rainwater conveyance piping labeling and marking shall comply with Section 1301.6.

1303.15 Tests and inspections.

Tests and inspections shall be performed in accordance with Sections

108

,

312

, and Sections 1303.15.1 through 1303.15.9. Special inspections of the nonpotable water systems shall be conducted in accordance with

Chapter 17

of the

New York City Building Code

.

1303.15.1 Reserved.

1303.15.2 Roofwasher test.

Roofwashers shall be tested by introducing water into the gutters. Proper diversion of the first quantity of water in accordance with the requirements of Section 1303.4 shall be verified.

1303.15.3 Collection pipe and vent test.

Drain, waste and vent piping used for rainwater collection and conveyance systems shall be tested in accordance with Section

312

.

1303.15.4 Storage tank test.

Storage tanks shall be tested in accordance with Section 1301.9.11.

1303.15.5 Water supply system test.

The testing of makeup water supply piping and conveyance piping shall be conducted in accordance with Section 312.5.

1303.15.6 Inspection and testing of backflow prevention assemblies.

The testing of backflow preventers and backwater valves shall be conducted in accordance with Section 312.10.

1303.15.7 Inspection of vermin and insect protection.

Inlets and vents to the system shall be inspected to verify that each is protected to prevent the entrance of insects and vermin into the storage tank and piping systems in accordance with Section 1301.7.

1303.15.8 Water quality test.

Water quality testing and monitoring shall be conducted in accordance with requirements of the Department of Health and Mental Hygiene.

1303.15.9 Inspection and testing of cross connection control.

Cross connection control inspection and testing shall be conducted in accordance with the requirements of the Department of Health and Mental Hygiene.

1303.16 Operation and maintenance manuals.

Operation and maintenance manuals shall be supplied with rainwater collection and conveyance systems in accordance with Sections 1303.16.1 through 1303.16.4.

1303.16.1 Manual.

A detailed operations and maintenance manual shall be supplied in hardcopy form with all systems.

1303.16.2 Schematics.

The manual shall include a detailed system schematic, and locations and a list of all system components, including manufacturer and model number.

1303.16.3 Maintenance procedures.

The manual shall provide a maintenance schedule and procedures for all system components requiring periodic maintenance. Consumable parts, including filters, shall be noted along with part numbers.

1303.16.4 Operations procedures.

The manual shall include system startup and shutdown procedures. The manual shall include detailed operating procedures for the system.